Referral criteria from primary care - kidney disease

NICE suggest referral criteria for patients with CKD as (1):

• people with CKD in the following groups should normally be referred for specialist assessment:
  
  
  • a 5-year risk of needing renal replacement therapy of greater than 5% (measured using the 4-variable Kidney Failure Risk Equation)
    • NICE have suggested that referral be based on use of the four-variable Kidney Failure Risk Equation instead of eGFR threshold for referral
      • a person's 5-year risk of needing renal replacement therapy (defined as the need for dialysis or transplant) is estimated, as in Major 2019
        • equation and its coefficients are validated in a UK population, and it is important to use this version, and not a version validated in another country
          
  • an ACR of 70 mg/mmol or more, unless known to be caused by diabetes and already appropriately treated
  • an ACR of more than 30 mg/mmol (ACR category A3), together with haematuria
  • a sustained decrease in eGFR of 25% or more and a change in eGFR category within 12 months
  • a sustained decrease in eGFR of 15 ml/min/1.73 m2 or more per year
  • hypertension that remains poorly controlled (above the person's individual target) despite the use of at least 4 antihypertensive medicines at therapeutic doses
  • known or suspected rare or genetic causes of CKD
  • suspected renal artery stenosis
    
    
• Refer children and young people with CKD for specialist assessment if they have any of the following:
  • an ACR of 3 mg/mmol or more, confirmed on a repeat early morning urine sample
  • haematuria
  • any decrease in eGFR
  • hypertension
  • known or suspected rare or genetic causes of CKD
  • suspected renal artery stenosis
  • renal outflow obstruction
    
    
• people with CKD and renal outflow obstruction should normally be referred to urological services, unless urgent medical intervention is required - for example, for the treatment of hyperkalaemia, severe uraemia, acidosis or fluid overload

More detailed guidance regarding nephrology referrals was previously stated as (2):

• Immediate review
  • if suspected acute renal failure (ARF)
  • if ARF superimposed on CKD
  • if newly detected ERF (GFR < 15 mL/min/1.73 m2)
  • accelerated or malignant phase hypertension with suspicion of underlying kidney disease (or if there is no specialist hypertension service available locally)
  • hyperkalaemia, serum potassium >= 6.5 mmol/L (3)
• Urgent outpatient review
  • nephrotic syndrome
  • if newly detected stage 4 (unless known to be stable) or stable stage 5 CKD
  • multisystem disease (e.g. SLE, systemic vasculitis) with evidence of kidney disease
  • hyperkalaemia, serum potassium 6.0-7.0 mmol/L (after exclusion of artefactual and treatable causes)
• Routine outpatient review
  • refractory hypertension (defined as sustained BP >150/90 mm Hg despite combination therapy with 3 drugs from complementary classes)
  • acute deterioration in kidney function (defined as a fall of GFR of >20% or rise of serum creatinine concentration of >30% from baseline) associated with use of ACEIs or ARBs
  • proteinuria (urine protein >100 mg/mmol) without nephrotic syndrome
  • proteinuria with haematuria
  • diabetes with increasing proteinuria but without diabetic retinopathy
  • stage 3 CKD with haematuria
  • urologically unexplained macroscopic haematuria (with or without proteinuria)
  • recurrent unexplained pulmonary oedema with clinical suspicion of atherosclerotic renal artery stenosis (ARAS)
  • falling GFR (>15% fall over 12 months) with clinical suspicion of ARAS
  • PTH >70 ng/L (7.7 pmol/L) after exclusion or treatment of vitamin D deficiency
  • stable stage 4 CKD if referred
• Conditions appropriate for GP care +/- 'virtual' nephrology support/advice  
  • isolated microscopic haematuria (after negative urological evaluation where appropriate)
  • isolated proteinuria with urine protein:creatinine ratio < 100 mg/mmol
  • known or suspected polycystic kidney disease with GFR > 60 ml/min/1.73 m2
  • known reflux nephropathy in stage 1-3 without the above
  • all other stage 1-2 CKD
  • stable stage 3 or 4 CKD with no other indication for referral

Notes (3):

• the threshold for emergency treatment varies, but most guidelines recommend that emergency treatment should be given if the serum K+ is >= 6.5 mmol/L with or without ECG changes

Reference:

1. NICE (August 2021). Chronic kidney disease: assessment and management
2. The Renal Association (2007).UK CKD Guidelines
3. The Renal Association UK (March 2014). The management of hyperkalaemia in adults.